Paginator
Django provides a few classes that help you manage paginated data – that is,data that’s split across several pages, with “Previous/Next” links. Theseclasses live in django/core/paginator.py.
Paginator class
- class
Paginator
(object_list, per_page, orphans=0, allow_empty_first_page=True)[source] Paginator.
object_list
- Required. A list, tuple,
QuerySet
, or other sliceable object with acount()
orlen()
method. For consistent pagination,QuerySet
s should be ordered, e.g. with anorder_by()
clause or with a defaultordering
on the model.
Performance issues paginating large QuerySet
s
If you’re using a QuerySet
with a very large number of items,requesting high page numbers might be slow on some databases, becausethe resulting LIMIT
/OFFSET
query needs to count the number ofOFFSET
records which takes longer as the page number gets higher.
Paginator.
per_page
Required. The maximum number of items to include on a page, not includingorphans (see the
orphans
optional argument below).Optional. Use this when you don’t want to have a last page with very fewitems. If the last page would normally have a number of items less than orequal to
orphans
, then those items will be added to the previous page(which becomes the last page) instead of leaving the items on a page bythemselves. For example, with 23 items,per_page=10
, andorphans=3
,there will be two pages; the first page with 10 items and the second(and last) page with 13 items.orphans
defaults to zero, which meanspages are never combined and the last page may have one item.- Optional. Whether or not the first page is allowed to be empty. If
False
andobject_list
is empty, then anEmptyPage
error willbe raised.
Methods
Paginator.
getpage
(_number)[source]- Returns a
Page
object with the given 1-based index, while alsohandling out of range and invalid page numbers.
If the page isn’t a number, it returns the first page. If the page numberis negative or greater than the number of pages, it returns the last page.
Raises an EmptyPage
exception only if you specifyPaginator(…, allow_empty_first_page=False)
and the object_list
isempty.
Paginator.
page
(number)[source]- Returns a
Page
object with the given 1-based index. RaisesInvalidPage
if the given page number doesn’t exist.
Attributes
Note
When determining the number of objects contained in object_list
,Paginator
will first try calling object_list.count()
. Ifobject_list
has no count()
method, then Paginator
willfall back to using len(object_list)
. This allows objects, such asQuerySet
, to use a more efficient count()
method whenavailable.
Paginator.
num_pages
The total number of pages.
- A 1-based range iterator of page numbers, e.g. yielding
[1, 2, 3, 4]
.
Page class
You usually won’t construct Page
objects by hand – you’ll get them usingPaginator.page()
.
- class
Page
(object_list, number, paginator)[source] - A page acts like a sequence of
Page.object_list
when usinglen()
or iterating it directly.
Methods
Page.
has_next
()[source]Returns
True
if there’s a next page.Page.
has_previous
()[source]Returns
True
if there’s a previous page.Page.
has_other_pages
()[source]Returns
True
if there’s a next or previous page.Page.
next_page_number
()[source]Returns the next page number. Raises
InvalidPage
if next pagedoesn’t exist.Page.
previous_page_number
()[source]Returns the previous page number. Raises
InvalidPage
if previouspage doesn’t exist.Page.
start_index
()[source]Returns the 1-based index of the first object on the page, relative to allof the objects in the paginator’s list. For example, when paginating a listof 5 objects with 2 objects per page, the second page’s
start_index()
would return3
.Page.
end_index
()[source]- Returns the 1-based index of the last object on the page, relative to allof the objects in the paginator’s list. For example, when paginating a listof 5 objects with 2 objects per page, the second page’s
end_index()
would return4
.
Attributes
Page.
object_list
The list of objects on this page.
The 1-based page number for this page.
- The associated
Paginator
object.
Exceptions
- exception
InvalidPage
[source] - A base class for exceptions raised when a paginator is passed an invalidpage number.
The Paginator.page()
method raises an exception if the requested page isinvalid (i.e. not an integer) or contains no objects. Generally, it’s enoughto catch the InvalidPage
exception, but if you’d like more granularity,you can catch either of the following exceptions:
- exception
PageNotAnInteger
[source] Raised when
page()
is given a value that isn’t an integer.exception
EmptyPage
[source]- Raised when
page()
is given a valid value but no objectsexist on that page.
Both of the exceptions are subclasses of InvalidPage
, so you can handlethem both with except InvalidPage
.